@Naim.F.C
Thanks for such a thorough and helpful comparison.
I read that the g2 was produced in response to some people finding peaky treble in the g1, but, as ever, it must depend on the rest of your kit as well of course as our ears etc, etc.
Unfortunately, there is a fine balance between producing lots of air and detail and risking troublesome treble. The same happened with the HD800 and 800S.
I went for the g2 as I have quite a lot of Classical which I find can be quite treble bright at times, especially badly recorded violins in Chamber Music, which seem to be the scourge of sound engineers.
Reviewers talk about headphones 'opening a window' to the sound, but for me the g2 opens up a whole room, like walking into a studio or concert hall, as the music completely engulfs me.
I think this is what you meant by the g2 being encapsulating. It took me by surprise the first time I used them as it was, for me, a unique experience using headphones, but since then I've read others, like yourself, experiencing this.